In cinema special attention must be paid to continuity because films are rarely shot in the order in which they are presented: that is, a crew may film a scene from the end of a movie first, followed by one from the middle, and so on. The shooting schedule is often dictated by location permit issues. Continuity is particularly a concern in the production of film and television due to the difficulty of rectifying an error in continuity after shooting has completed. Most productions have a script supervisor on hand whose job is to pay attention to and attempt to maintain continuity across the chaotic and typically non-linear production shoot. This takes the form of a large amount of paperwork, photographs, and attention to and memory of large quantities of detail, some of which is sometimes assembled into the story bible for the production. It usually regards factors both within the scene and often even technical details including meticulous records of camera positioning and equipment settings. The use of a Polaroid camera was standard but has since been replaced by the advent of digital cameras. All of this is done so that ideally all related shots can match, despite perhaps parts being shot thousands of miles and several months apart. It is a less conspicuous job, though, because if done perfectly, no one will ever notice.